Toby, we can go up the Columbia only a few miles before it becomes to shallow to navigate. We can go down the Columbia 325 miles to the Pacific. We've been downstream to Portland, OR (230 miles) twice.
A few miles downstream of our marina the Snake River dumps into the Columbia. I've boated all 155 miles from where the Snake ends up to Lewiston, ID. Pretty country that looks much like those pics of the barren hills.
Between here and Portland there are four USCOE dams and four more along the Snake River. They're fun to go through and a bit overwhelming the first couple of times.
On an unrelated note, I google mapped Hope, ID to find out where it is. I found it on the shores of Lake PO. Last summer we took our 13' Whaler up there, staying at Bayview. We took the Whaler from Bayview up to Sandpoint, had some lunch and returned to Bayview. Beautiful lake, some beautiful homes along the way, and some gorgeous scenery. Nice country you live in up there!
Mike and Tina
Beachcomber 1995 Sea Ray 550 Sedan Bridge